Book/Report FZJ-2019-04549

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png
Genetische und physiologische Untersuchungen zur Pantothenat- und Valinbildung in Corynebacterium glutamicum



1998
Forschungszentrum Jülich, Zentralbibliothek, Verlag Jülich

Jülich : Forschungszentrum Jülich, Zentralbibliothek, Verlag, Berichte des Forschungszentrums Jülich 3606, 115 p. ()

Please use a persistent id in citations:

Report No.: Juel-3606

Abstract: The Gram-positive bacterium Corynebacterium glutamicum is used for the production of amino acids, e.g. of L-glutamate and L-lysine. The aim of my work was to elucidate the biosynthetic pathway of pantothenic acid of this organism, and to increase the formation of L-valine and D-pantothenic acid in order to enable a microbiological production of these compounds. The genes panB and panC euere cloned, which encode the ketopantoatehydroxy-methyltransferase and the pantothenatesynthetase. The two enzymes catalyze important steps of the biosynthetic pathway of pantothenate. Sequence analysis revealed that panB comprises 813 bp and panC 837 bp. The genes are organized as an operon. Assays for the enzymes of the pathway haue been developed. Thepantothenatesynthetase has a specifc activity of 1 nmol/(min$\ast$mg protein), the ketopantoatehydroxymethyltransferase one of 0.14 nmol/(min$\ast$mg protein) and the aspartate-$\alpha$-decarboxylase one of 0.11 nmol/(min$\ast$mg protein). The quantitative analysis of the formation of pantothenic acid revealed that C. glutamicum accumulates 10 $\mu$g/l pantothenic acid. A system to isolate mutants with an increased formation pantothenate, which is based on a deficiency of pantothenic acid induced by $\alpha$-ketobutyrate, has been established. The application of this method led to the isolation of a mutant which accumulates 250 $\mu$g/l pantothenate and 1.4 g/l valine. Overexpression of the genes of the valine and isoleucine biosynthetic pathway (ilvBNCD), in combination with the deletion of the threonine dehydratase gene ilvA resulted in the construction of a strain which accumulates 11,3 g/l valine and 190 mg/l pantothenate. Additional overexpression of panBC led to an accumulation of up to 1 g/l pantothenic acid. Thus an increase of the formation of pantothenic acid in C. glutamicum by the factor of 10$^{5}$ has been achieved.


Contributing Institute(s):
  1. Publikationen vor 2000 (PRE-2000)
Research Program(s):
  1. 899 - ohne Topic (POF3-899) (POF3-899)

Database coverage:
OpenAccess
Click to display QR Code for this record

The record appears in these collections:
Document types > Reports > Reports
Document types > Books > Books
Workflow collections > Public records
Institute Collections > Retrocat
Publications database
Open Access

 Record created 2019-09-04, last modified 2021-01-30